1. Field of the Invention
This invention relates to a rotary driving device wherein a movement of an input shaft is imparted to an output shaft as a rotation only in one direction.
2. Description of the Prior Art
As a rotary driving device wherein a movement of an input shaft, e.g. a rotation is imparted to an output shaft as a rotation in one direction, there has heretofore been known a one-way clutch. This one-way clutch has been provided in a bearing portion of a rear wheel of a bicycle for example. In the bicycle provided with the one-way clutch, a rotation of a pedal of a body frame is transmitted to a rear wheel through a sprocket and a chain to obtain a driving force. However, such disadvantages have been presented that the number of parts as a whole increases, so that the one-way clutch cannot be provided inexpensively, and further, the chain and the like cannot be completely sealed, so that maintenance cannot be made completely free. The above-described situation is true of a roller-through, a buggy, a handle-driven wheelchair and the like, in addition to the bicycle. Furthermore, the one-way clutch has been disadvantageous in that the side, to which is not imparted a rotation, during rotation, a rotary force is relieved through an engaging pawl against the resiliency of a spring, thus increasing loss of energy.